The U.S. Department of Labor (DOL) launched the American Apprenticeship Initiative (AAI) in October 2015 to expand registered apprenticeship into high-growth occupations and industries and to increase apprenticeship opportunities for all Americans. Apprenticeship is a structured, work-based training program that combines classroom instruction (“related technical instruction,” or RTI) with on-the-job learning (OJL) provided by a mentor at the employer’s worksite.